


Boum !

by Kealpos



Category: Singin' in the Rain (1952)
Genre: Multi, OT3, This is my.. first time writing for this so don't @ me, Threesome - F/M/M
Language: English
Status: Completed
Published: 2018-03-15
Updated: 2018-03-15
Packaged: 2019-03-31 15:46:34
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,572
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13978347
Author URL: https://archiveofourown.org/users/Kealpos/pseuds/Kealpos
Summary: Don shrugged before crossing over to him and sitting down at his feet. “I mean it. You’ve lived here so long, I still sometimes forget you pay for your own pad.”“Kathy didn’t even know I had one. Please. I’m not that much of a lollygagger.”





	Boum !

"Cosmo Brown!"  
A high, clear voice rang out across the set, causing the man in question to look up from his work. The studio, Monumental Pictures, had been filming for _Fool for Love_ for the past several days, and Mr. Brown (who resented being called that) had been holed up in his apartment or whatever studio room had a piano and wasn't being filmed on for a little less than that. Kathy Seldman, a close friend of Cosmo's and main actor for Fools had been hunting him down for the better part of thirty minutes.

Cosmo, head of the music department at Monumental, had been working on a few background scores that would play during the film's "straight" sections and had been almost impossible to pin down. Between the changing of room for a particular instrument, frequent pacing for brainstorming, and him sneaking off from the studio for a change of scenery, anyone desperate for him would be run ragged.

Kathy Seldman had barged into the set after some directional advice from some young man who seemed to be attempting to become a new ‘Don Lockwood’, even if the true Don was impossible to recreate in every way. She had a good-natured smile on her face, though her body language looked to be read as cross. Actors.

She walked her way over to where Cosmo sat at his piano, a pile of handwritten sheet music sitting on it. His mouth was a straight line, but his eyes twinkled happily and his eyebrow was raised at her.

“Cos, where’ve you been? Me and Don haven’t seen you for days! Not seeing you at studio, sure, we’ve all been busy, but you haven’t been over in a bit. Have you been staying here, or with a friend?”  
“Now, that’s all wet! The floors are cold as all can be, Kath, with not even a female impersonator to keep me warm. Not to mention, you know full well I have no friends besides you and Mister Lockwood,” he teased. “I’m almost insulted. But I’ve been at my apartment and staying up late into the night to work on this monster of a song for that serious moment.”

Kathy tilted her head at him as gears clicked away in her head. Finally, she leaned over and placed her arms on the piano, sagging against it. “You have your own place? I don’t think I’ve ever heard you mention it.”  
Cosmo’s expression became a mixture of confused, exasperated, and an unidentifiable sour emotion. That might’ve been the wrong thing to say.

“Of course I do. It's not very classy, and I can- could mooch off Don real easy so I hardly stay there, but I pay for it nonetheless, just in case my meal-ticket off and dies or I get kicked out, something like that. I figured I should stay there for the past couple of days cause of two reasons.”  
“Oh? Spill.”

“Well,” Cosmo started, leaning forwards, his body directed at her. “Since you’ve moved in permanently, one, I figure you don’t want to be kept up by my racket. Don’s used to it, but you haven’t exactly felt the full force of my noise quite yet, and you don’t want to.”  
“Baloney! Of course I do, Cos.”

Cosmo looked at her pointedly, slightly amused, before rebutting, “No, you really don’t. And point two: I figure you two lovebirds won’t want me hanging around the clock once you two finally go down the middle aisle. So, this way, us three will all be used to me being out by then.”

Kathy scrunched her nose at him, laughing slightly as if the notion itself were absurd. “What are you on about? You think we’ll get sick of you or something?”  
“And how! Even if why someone would get sick of my lovely habits, shining personality, and perfect comedic timing is quite hard for me to figure out,” he replied jokingly, though she could tell there was truth and insecurity in his statement.

“Well, we won’t,” she said decisively. “Not to mention, if we ever do, you know you’d get an earful about it. Me and that big timer, future Mr. Seldman, aren’t known for keeping things from our favorite piano player.”  
He chuckled lightly in response before turning his body to face the piano. “Any song requests?”

Kathy shook her head at the obvious change of subject, but brought her arms back down to her sides and sat next to Cosmo on the piano bench. “Mm, do you know “Don’t Take My Boop-Oop-A-Doop Away”?”  
“Do I?” He scoffed, before clanging on the keys and starting up the first couple of notes. She smiled softly and leaned into him until her head rested on his shoulder. It kept moving so that he could hit the keys, but she didn’t seem to mind, and neither did he.

-

“Cos, how would you feel about a pet?”  
“I feel like it would make my excuses about having to see a man about a dog a lot more truthful.”

Don Lockwood leaned against the frame of the doorway and sighed in the way that was supposed to tell people off, but Cosmo totally ignored. His friend was sitting in front of him lounging slightly as he plucked at a guitar in the “music room” of Don’s house. Cosmo still had fits about him insisting it would always be the music room, as he knew that his stay would be temporary.

“No, I mean seriously. I’ve been feeling like bringing a cat into this place.”  
“It’s yours and Kathy’s house, goof. I don’t care, and you don’t even need my input anyhow.”  
“Of course we do, it’s yours too.”

“Yeah, okay,” he replied mockingly before playing a few more notes.  
Don shrugged before crossing over to him and sitting down at his feet. “I mean it. You’ve lived here so long, I still sometimes forget you pay for your own pad.”  
“Kathy didn’t even know I had one. Please. I’m not that much of a lollygagger.”

“Just drop the apartment and maybe we can convince you to stop calling your room the guest bedroom. It stores almost every single one of you things, Cos.”  
“Listen, I don’t get what’s up with you and Kathy, but I,” he said, picking at the strings, “do not like you dragging me into it. Why are you two so insistent that I stay by all the time? I thought almost married couples didn’t want some bum hanging around. That’s how my parents were regarding me, ha!”

Don reached his arm up and rested it on Cosmo’s leg, which made him clam up just a bit. He always seemed surprised when anyone initiated any kind of physical contact, but he quickly relaxed into the touch like he always did.

“Mm, we just don’t want you slipping away from us. You know we adore you, right?”  
“Oh yeah? Boy Don, I’m just so over the moon I could sing. Charles Trenet!”  
“No, don’t-” Don laughed, trying to sit up and stop him.

“Quand notre cœur fait boum, tout avec lui dit boum, et c'est l'amour qui s'éveille!” Cosmo sang, well, wailed before Don could get him to stop. Finally, he managed to wrench the guitar out from his terrible, terrible hands, but he stood up to continue.  
“Boum! Il chante "Love in Bloom", au rythme de ce boum, qui redit boum à l'oreille!” He gave Don a sly grin before offering his hand to help him up, which he jokingly refused.

After Don staggered up, the two stood to face each other. Cosmo’s hands were shoved in his pockets and Don’s hair was a mess, looking entirely unprofessional.  
“There’s the Lockwood I like. As much as I’d like to stay, I, well, have to see a man about a dog, and then get some sleep before I crank out music tomorrow.”

Don’s face softened and his eyes drooped, along with his smile. Cosmo turned to walk away, but he touched his arm for a second, keeping it there for a moment, which Cosmo raised his eyebrow at.  
“I’m serious, Cos. It’s your home as much as mine and Kathy’s.”

Cosmo chuckled, his eyes light and dazzled.  
“You’ll have to kill me to get me out of here now.”

(“You actually got a dog!?” Kathy exclaimed, though not mad, just delighted. Cosmo had just shrugged with a lazy smile pulled across his profile, and she had kissed him on the cheek. His eyes twinkled just a little bit brighter.)

-

“He’s zozzled out of his mind, Don. I don’t trust him to stay in the room where we both know he keeps his booze.”  
“His bedroom, Kathy.”  
“Regardless!”

The two were smushed together and whispering about Cosmo, who had come back drunk from some thing. Lilyan, their pug, had managed to distract the piano player. He had been rubbing her back for almost two minutes

“So, what should we do? Should I take it all out?”  
“Would you? I can keep him busy.”  
“That wasn’t sincere, me saying that, but you really do know how to put on the beggar eyes, huh?”

Kathy shrugged her shoulders with a light smile before crossing over to the couch, where Cosmo sat with Lilyan now on his lap. Don heaved overdramatically before rushing into Cosmo’s room to empty it of alcohol while she sat down next to him. Lilyan turned her head and waggled over to her, so she scooted in slightly closer.

Cosmo gave her an exceptionally dopey smile and in a woozy voice had spoken, “Kathy, cash or check?” before giggling at her and leaning back into the couch.  
“Hm, I would usually be all for it right now, but I’ll have to check until you’re no longer fried,” she murmured, grinning.

“Oh. You would normally though?”  
“Pos-i-lute-ly.”  
“Good! Maybe- maybe I’ll, uh, hold you to that. Maybe,” Cosmo yawned, “Don wouldn’t mind. Do you think he’d be mad about it? Ohh, he probably would, as you’re his wife and- and all.”

The two had finally gotten married the previous month and a half with a great big Hollywood wedding at the demands of the Monumental studio head and his grinning team of demons they called the publicity team’s demands. They had taken a three-week-long honeymoon to Europe and had dragged the best man- Cosmo -along with them.  
“I don’t think he would,” she said lightly.

Cosmo only hummed in response before going quiet, and Kathy let him, Lilyan curled up next to her. She tucked her legs up slightly and leaned towards him, reached up a hand, and began to slowly pet his hair. He let her do that.

-

“The dog peed in the bed,” Cosmo groaned as he trudged into the kitchen one evening as Don and Kathy ate dinner consisting of leftovers from the previous day. “I can’t sleep there tonight. Will one of you dames be so kind as to offer me a blanket and pillow for my rest on the couch later?”

The ‘two dames’ glanced at each other for a moment before Don looked back and swallowed his food. “Just sleep with us tonight. The bed is big enough for three and sleeping on there is hell.”  
“What!?” Cosmo exclaimed before sputtering for a second. “No. You and me, we shared beds for vaudeville, but I’m not going to make Kath uncomfortable for my own sake.”

She and Don had caught on to something with Cosmo a few months before and had been trying to get him to catch on to their side for almost as long, so she just grinned slyly and brought her elbows forwards to rest on them.  
“Oh, I don’t mind one bit, Cos. Come join us tonight, it doesn’t have to be a big deal unless you make it one.”

Then, with all the charm and perfection two Hollywood stars could give, both Kathy and Don gave him bright yet pouty smiles right on cue. Cosmo held up against both of them for a total of five seconds, with his record being a full forty seconds.  
“Fine, you two really intend on showing a lady a good time with those smiles, I expect,” Cosmo joked as he looked away from their intense gazes, but Kathy and Don felt victorious.

The rest of the evening went normally, with Cosmo eating his own dinner and putting his sheets into the wash, followed by Kathy and Don performing some lines for one another and Cos, sending Lilyan out for a few minutes, and then heading to bed.

Cosmo seemed even more slouched over than usual as he stalked into Don and Kathy’s room, wearing his striped pajamas, which Don and Kathy immediately objected to (“I’ve seen you right after you wake up, Cos! Just sleep in your damn boxers, I swear I don’t mind at all.”).

After working out spacing, the three finally settled down, Cosmo curled in between the two of them. He was out quickly, breathing heavily next to Don. Lockwood gave Kathy a finally sleepy smile before joining him in the land dreams, she following soon after. The bed was warm that night, and Don found he had clung to Cosmo in the middle of it, as he was stirred awake by movement from him.

Don opened his eyes slowly and only partially, but could make out Cosmo’s figure at the front of the bed, hunched over, tapping his fingers to some sort of beat on the mattress. Don yawned quietly before reaching across to Kathy and shaking her softly and weakly, which woke her up nonetheless.

Kathy made a little noise as she came to life which got Cosmo to turn and look at her, his eyes wide. Don shifted slightly and pushed himself up, blinking tiredness out of his eyes. What time was it? She mimicked him, only sitting up further, and Cosmo turned around all the way.

“What’s eating you, buddy?” Don asked softly, his voice raspy from sleep and full of concern and love. Cosmo replied only with a watery smile, so he pulled himself out of the sheets and crawled forwards. Kathy was smiling softly and followed after him, and within seconds, both were next to Cosmo and leaning into him.

“Don- Kathy-” He started, seemingly unable to finish his thoughts, so the two just placed their arms gently around him. It was hard to see, but Don could feel his eyes adjusting slowly, and it became easier to find little details on Cosmo’s torso.  
“Please you two, you really don’t have to humor me,” he said quietly and without joking, but there was some hope that it seemed to be soaked in.

“Oh Cos,” Kathy murmured softly, and both she and Don moved in extra close and kissed him. Don hit his jawline, and Kathy managed to get his shoulder/collarbone. He let out a soft, gentle sigh that sounded like pure heaven to Kathy, and like a warm bath after a long day to Don.

The three curled up together until the sun became visible in the window, occasionally giving one another a new kiss, and a little bit longer. They finally split apart because Cosmo moved and pulled his arms out and up, stretching them with a dopey little grin on his face. As they got dressed, they caught him humming ‘I Wanna Be Loved By You’ and they smiled at one another.

 

**Author's Note:**

> https://don-lockwood.tumblr.com


End file.
